can i upgrade..or improve a all?

[cadman33619]

Hi all.
I have a iphone 3G (jb and unlocked). its been a while since i've done anything to it and i was just wondering if i can upgrade the IOS or improve it at all.

specs:
version 4.2.1 (8c148)
model MB046LL
firmware 06.15.00

thanks

 

[TriJetHero]

Nope, 4.2.1 is the highest the 3 goes.